WO2016078817A1

WO2016078817A1 - Sensor for analyzing an exhaust gas of an internal combustion engine, internal combustion engine, and method and device for producing such a sensor

Info

Publication number: WO2016078817A1
Application number: PCT/EP2015/072800
Authority: WO
Inventors: Denis Kunz; Markus Widenmeyer; Tino Fuchs; Robert Roelver
Original assignee: Robert Bosch Gmbh
Priority date: 2014-11-21
Filing date: 2015-10-02
Publication date: 2016-05-26
Also published as: DE102014223780A1; EP3221686A1

Abstract

The invention relates to a sensor (100) for analyzing an exhaust gas of an internal combustion engine (500). For this purpose, the sensor (100) comprises a cover element (102), which has, in a filter region (106), a plurality of pores (108) for filtering particles out of the exhaust gas, a measuring electrode (110) arranged on the cover element (102) for determining a particle concentration in the exhaust gas, a heating element (112) arranged on the cover element (102) for heating the filter region (106) and/or the measuring electrode (110), and a bottom element (104), which has at least one sensor element (118) for determining a gas concentration in the exhaust gas. The sensor element (118) is covered by the cover element (102) in order to prevent an accumulation of the particles on the sensor element (118). The sensor element (118) is fluidically coupled to an outer environment of the sensor (100) by means of the filter region (106).

Description

Description title

Sensor for analyzing an exhaust gas of an internal combustion engine, internal combustion engine, and method and apparatus for producing such a sensor

State of the art

The present invention relates to a sensor for analyzing an exhaust gas of an internal combustion engine, to a

Internal combustion engine, to a method for producing a sensor for analyzing an exhaust gas of an internal combustion engine, to a corresponding device and to a corresponding computer program.

By means of a so-called lambda probe, a residual oxygen content in the exhaust gas of internal combustion engines can be measured and used to determine a

Combustion air ratio can be used. By an engine control, the combustion air ratio can be adjusted so that the proportion of pollutants in the exhaust gas, such as nitrogen oxides, is as low as possible.

For example, DE 10 2005 015 103 A1 describes a lambda probe with a ceramic sensor element.

Disclosure of the invention

Against this background, with the approach presented here, a sensor for analyzing an exhaust gas of an internal combustion engine, an internal combustion engine, a method for producing such a sensor, a device that uses this method, and finally a corresponding computer program according to the Main claims presented. Advantageous embodiments emerge from the respective subclaims and the following description.

The approach proposed here provides a sensor for analyzing an exhaust gas of an internal combustion engine, the sensor having the following

Characteristics comprising: a lid member having a plurality of pores in a filter region for filtering out particulate matter from the exhaust gas; a measuring electrode disposed on the lid member for determining a particle concentration in the exhaust gas; a heating element arranged on the lid element for heating the filter area and / or the measuring electrode; and a bottom member having at least one sensor element for determining a gas concentration in the exhaust gas, the cover member having the

Sensor element covers to prevent accumulation of the particles on the sensor element, and wherein the sensor element is coupled via the filter region fluidly with an external environment of the sensor.

An exhaust gas may be used in a combustion process in the

Internal combustion engine accumulating, no longer usable gas mixture are understood. Under an internal combustion engine, a

Heat engine such as an internal combustion engine or a

Turbomachine be understood. Under a cover element and a bottom element can each be understood a layer of a heat-resistant material, such as a semiconductor material. The cover and the bottom element can be combined with one another, for example, in a layer composite. A pore can be understood as meaning a through opening in the cover element. Under a particle can be a solid

Part of the exhaust gas such as soot or dust are understood. The measuring electrode may for example be formed from a wire, on which the particles can accumulate from the exhaust gas. The particle concentration can for example, by measuring a change in resistance at the

Measuring electrode can be determined. Under a heating element, a

Heating electrode, be understood in the form of a wire or metal strip, which generates heat when an electrical voltage. The heating element can be used for regeneration of the filter area and, additionally or alternatively, for regeneration of the measuring electrode. The sensor element may, for example, be realized as a Nernst probe in order to determine the gas concentration, in particular an oxygen concentration, in the exhaust gas.

The approach presented here is based on the knowledge that a sensor for determining a gas concentration in an exhaust gas of a

Internal combustion engine with a protective layer to protect a

Sensor element of the sensor can be realized against contamination. The protective layer may be a gas-permeable, porous region for

Have particle filtering. By a suitable arrangement of a heating element and a measuring electrode on the protective layer, the protective layer can be used both as a particle filter and as a particle sensor for determining a

Particle concentration in the exhaust act.

For example, the sensor element can be realized as a lambda probe.

According to one embodiment, the sensor may be constructed monolithically to the functions lambda probe, soot particle protection of the lambda probe and

Soot particle sensor to link together. This makes the sensor very compact. In addition, thereby the production costs can be significantly reduced.

To protect against soot and water hammer, the lambda probe can be covered by a cover element in the form of a porous, heatable protective cap. The protective cap can act as a filter cap to filter out soot particles from a respective sample gas. An integrated into the cap

Heater can serve to burn off accumulated soot particles to the

Regenerate filter cap.

By way of example, the soot particle sensor may be realized from interdigital contact structures and be designed to vary depending on a Resistance change to detect a soot load. Advantageously, the soot particle sensor can be regenerated in the same way as the filter cap by means of the heater. By a lambda measurement, a residual oxygen content in the exhaust gas of a

Internal combustion engine are measured and a corresponding measurement with an engine control are fed back to minimize pollutants such as nitrogen oxides in the exhaust gas of internal combustion engines. For this purpose, ceramic lambda probes are generally used, which are produced, for example, in thick film technology using zirconia-based ceramics. The

Dimensions of such a ceramic sensor element are usually in the range of 5 mm by 5 mm, with a thickness of about 1 mm to 2 mm.

To protect the sensor element and peripheral electrical connections from stresses such as corrosive exhaust, soot deposits, high temperatures and

To protect mechanical loads, the sensor surface is typically dimensioned so large, approximately in the square millimeter range that individual local soot deposits do not immediately lead to sensor failure. Furthermore, the sensor surface can be provided with a porous covering layer several micrometers thick, which prevents sensor poisoning by corrosive exhaust gas constituents.

In contrast, the approach presented here makes it possible to realize a miniaturized gas sensor, for example a microelectrochemical (MECS) solid-state electrolyte which can be produced in micromechanical processes and processes.

Gas sensor. Thereby, the size of the sensor element can be significantly reduced, for example, to about 1 mm by 2 mm by 1 mm (width times height times depth). An active solid electrolyte layer may have a thickness of only 100 nm to 1 μηη.

On the one hand, such a reduced installation space offers the advantage of a quick operational readiness of, for example, less than 3 seconds and a low heating power of, for example, 100 mW. On the other hand, it is thereby possible to use several miniaturized sensor elements with different

Functions in the sensor to unite, such as the additional monitoring of a Nitrogen oxide concentration. Since the construction and connection technology in the

Flue gas sensors make up a large proportion of the total production costs, such integration also brings a significant cost advantage. According to one embodiment of the proposed approach, the

Filter region to be arranged opposite the sensor element. As a result, the coupling of the sensor element to a measuring gas contained in the exhaust gas can be improved. In addition, the sensor can be constructed very compact in this way.

It is also advantageous if the measuring electrode and, additionally or alternatively, the heating element at least partially framing the filter area, in particular enclosing except for an access opening. As a result, the measuring electrode or the heating element can be arranged as space-saving as possible on the cover element, d. h., a dead volume above the sensor element can be minimized.

At the same time, the filter region or the measuring electrode can be heated efficiently in this way. In order to ensure a uniform and simultaneous heating of the measuring electrode and the filter area by the heating element, at least a majority of the measuring electrode can run between the heating element and the filter area.

According to a further embodiment, the measuring electrode as

Interdigitalelektrode be executed. An interdigital electrode can be understood to mean an electrode having a finger-like interlocking contact structure. As a result, the measuring electrode can be realized with a large surface area while still requiring little space.

Furthermore, it is advantageous if the cover element at least in

Filter region has a lid recess. In this case, the sensor element of the lid recess can be arranged opposite one another. Under one

Deckelausnehmung can be understood as a depression in the cover element. For example, the lid recess may be formed in that the lid member is performed in the filter area with a reduced wall thickness. In this way, the lid member can be formed cap-like with little manufacturing effort. Through the Deckelausnehmung the Heat capacity and thus the heating dynamics and the required heating power to achieve and maintain a certain temperature can be minimized.

The sensor element may include a bottom recess in the bottom element and an electrolyte layer of a first electrode, a second electrode and an electrode disposed between the first electrode and the second electrode

Include electrolyte. The electrolyte layer may cover the bottom recess to a chamber for receiving a reference gas or

Form reference gas mixture. The reference gas or reference gas mixture can serve as a reference for determining the gas concentration in the exhaust gas. In this case, the first electrode can be acted upon by the reference gas or reference gas mixture and the second electrode can be acted upon by the exhaust gas via the filter region. The reference gas or gas mixture can either be a separate gas or gas mixture introduced into the chamber, such as ambient air, or else a reference that can be produced by means of the electrolyte layer, for example an oxygen reference for determining an oxygen concentration in the exhaust gas. In this way, the sensor element can be realized in a cost-effective and space-saving manner as a Nernst probe or voltage jump probe.

It is advantageous if the sensor has at least one further heating element for heating the electrolyte layer. By means of the further heating element, a temperature-dependent ion diffusion through the electrolyte layer can be controlled. Depending on the embodiment, the further heating element and the heating element may be connected to each other in series or in parallel. As a result, the manufacturing cost of the sensor can be reduced.

The lid member may be made of a semiconductor material. Additionally or alternatively, the bottom element may be made of the semiconductor material. The semiconductor material may be about silicon. As a result, the sensor can be realized in a particularly cost-effective and compact manner.

Furthermore, the approach presented here creates an internal combustion engine with a sensor according to one of the embodiments described here. Finally, the proposed approach provides a method for manufacturing a sensor for analyzing an exhaust gas of a

Internal combustion engine, the method comprising the steps of:

Forming a composite of a bottom element, the at least one

Sensor element for determining a gas concentration in the exhaust gas, a cover member having a plurality of pores for filtering out particulates from the exhaust gas in a filter region, a measuring electrode for determining a particle concentration in the exhaust gas and a heating element for heating the filter region and / or the Measuring electrode, wherein the

Measuring electrode and the heating element are arranged on the cover element, wherein the cover element covers the sensor element to a

Preventing accumulation of the particles on the sensor element, and wherein the sensor element is fluidly coupled via the filter area with an external environment of the sensor.

The approach presented here also provides a device which is designed to implement the steps of a variant of a method presented here

to implement, control or implement appropriate facilities. Also by this embodiment of the invention in the form of a device, the object underlying the invention can be solved quickly and efficiently.

In the present case, a device can be understood as meaning an electrical device which processes sensor signals and outputs control and / or data signals in dependence thereon. The device may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the device. However, it is also possible that the interfaces have their own, integrated

Circuits are or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules. Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the above

described embodiments, in particular when the program product or program is executed on a computer or a device. The approach presented here will be described below with reference to the attached

Illustrated drawings by way of example. Show it:

Fig. 1 is a schematic cross-sectional view of a sensor according to an embodiment of the present invention;

Fig. 2 is a schematic representation of a sensor according to a

Embodiment of the present invention in plan view;

3a, 3b, 3c, 3d schematic cross-sectional views of a

Cover element of a sensor according to an embodiment of the present invention in various stages of production;

4 is a schematic cross-sectional view of a bottom element of a sensor according to an embodiment of the present invention;

5 shows a schematic representation of an internal combustion engine with a sensor according to an exemplary embodiment of the present invention;

6 is a flow chart of a method of manufacturing a sensor according to an embodiment of the present invention; and

Fig. 7 is a block diagram of an apparatus for performing a

Manufacturing method according to an embodiment of the present invention. In the following description of favorable embodiments of the present invention are for the in the various figures

represented and similar elements acting the same or similar

Reference numeral used, wherein a repeated description of these elements is omitted.

1 shows a schematic cross-sectional representation of a sensor 100 according to an embodiment of the present invention. The sensor 100 for analyzing an exhaust gas of an internal combustion engine includes a lid member 102 and a bottom member 104, which are according to this

Embodiment realized as layers and combined with each other in a composite layer. The cover element 102 has, in a filter region 106, only a plurality of pores 108, which are arranged, for example, in four columns and serve for filtering particles from the exhaust gas. On the lid member 102 are also a measuring electrode 110, here a

Interdigital electrode, and a heating element 112 arranged. In this case, the measuring electrode 110 is arranged between the heating element 112 and the filter region 106. The heating element 112 is designed to heat the measuring electrode 110 and the filter region 106 for cleaning particles that accumulate on the measuring electrode 110 or on the pores 108. The measuring electrode 110 is configured to determine a particle concentration in the exhaust gas.

The cover element 102 has on a side facing away from the heating element 112 and the measuring electrode 110 a lid recess 116, which in Fig. 1 by way of example in the region of the heating element 112, the measuring electrode

110 and the pores 108 extends. The lid member 102 is connected to the bottom member 104 such that the bottom member 104 is the

Cover recess 122 fluid-tight covering. About the pores 108 is the

Lid recess 122 is fluidly coupled to an external environment of the sensor 100.

The bottom element 104 comprises a sensor element 118, which is the

Cover recess 122 is disposed opposite and of the

Cover element 102 is enclosed. The sensor element 118 can via the Pores 108 are supplied with the exhaust gas to determine the concentration of a gas, such as oxygen, in the exhaust gas.

According to Fig. 1, the bottom element 104 as a sensor wafer and the

Cover element 102 as a cap wafer made of a semiconductor material,

For example, silicon, wherein the bottom member 104 and the cover member 102 may be connected to each other via wafer bonding. In this case, an optional insulation layer 119 on the cover element 102 serves to electrically insulate the heating element 112 and the measuring electrode 110 from the cover element 102.

If the sensor 100 is flown with the exhaust gas, so the particles contained in the exhaust gas such as soot or dust particles adhere to the one

Measuring electrode 110 at. The particle concentration in the exhaust gas can now be determined by a change in resistance of the measuring electrode 110, which of the at

Measuring electrode 110 adhering particle quantity is determined. On the other hand, the exhaust gas flows through the pores 108 in one of the

Deckelausnehmung 116 and the bottom member 104 limited cavity of the sensor 100, in which the sensor element 118 is arranged. In this case, at least a major portion of the particles contained in the exhaust gas remains attached to the pores 108. Thus, the sensor element 118 is subjected to a particle-free or at least low-particle exhaust gas.

According to the embodiment shown in FIG. 1, the sensor element 118 is designed as a Nernst probe. For this purpose, the bottom element 104 a

Floor recess 120, which is covered by an electrolyte layer 122. The electrolyte layer 122 is, for example, a layer composite comprising a first electrode 124, a second electrode 126 and an electrolyte 128 arranged between the electrodes 124, 126, in particular a solid electrolyte such as an yttrium-doped zirconium dioxide membrane (YSZ). The electrodes 124, 126 are realized for example as platinum electrodes. By way of example, the bottom recess 120 in FIG. 1 is arranged opposite the filter area 106. The bottom recess 120 forms, together with the electrolyte layer 122, a chamber 130 which, for example, with a reference gas or

Reference gas mixture is filled, hereinafter referred to as reference. In this case, the first electrode 124 can be acted upon by the reference and the second electrode 126 can be acted upon by the exhaust gas via the pores 108. Due to a concentration or partial pressure difference between the chamber 130 and the in the

Deckelausnehmung 116 introduced exhaust gas, it comes from a certain temperature of the electrolyte layer 122 to an ion diffusion through the electric layer 122. Here, ions migrate from the high concentration to the low

Concentration. A voltage applied between the electrodes 124, 126 can now be measured to determine the concentration of the gas in the exhaust gas.

Alternatively, the chamber 130 acts as a pumping cell to the reference

to provide, as explained in more detail below with reference to FIG. 4.

According to one exemplary embodiment of the present invention, the sensor 100 is used for measuring a lambda value and a soot particle load in the exhaust gas of internal combustion engines. For this purpose, the sensor 100 comprises a

microelectrochemical sensor element 118 with a heatable

Cap wafer as a lid member 102, also called protective cap or filter cap, and an interdigitated contact structure as a measuring electrode 110, English interdigitated electrodes or short ID called E.

Such a protective cap 102 protects the microelectrochemical sensor element 118 on the one hand from soot deposits by thermophoresis and active filtering of larger particles. In the filter area 106 deposited particles are burned during operation by active heating to above 800 ° C, thus preventing the blockage of the filter area 106. The additional protection against

Particle deposition by thermophoresis is also ensured by active heating as long as the filter cap temperature is above the immediate ambient temperature.

On the other hand, it is possible by the integration of the I DE structure 110, to measure the load of soot particles in the exhaust gas, as an increasing Soot particle accumulation leads to an electrical resistance change between the IDE contacts. This measured variable is output, for example, as an independent sensor signal. Will a certain threshold for the

Resistance between the isolated in the unloaded case IDE contacts below, so a heating process for burning the microelectrochemical cap 102 and the IDE contacts is triggered by a heating element acting as a heater 112 structure. The number of firing processes initiated is proportional to the soot load and can be used to control and diagnose an exhaust aftertreatment system.

FIG. 2 shows a schematic representation of a reference to FIG. 1

described sensor 100 according to an embodiment of the present invention in plan view. The sensor 100 has the heatable by means of the heating element 112, porous

Cap wafer 102 and realized as an interdigitated contact structure

Measuring electrode 110 on. A further heating element, not shown here, serves as a sensor membrane heater for heating the electrolyte layer. The further

Heating element and the heating element 112, here a platinum cap heater are connected via Heizdurchkontakte 200 with each other, here via silicon vias, through-silicon vias (TSV). As a result, the number of required electrical connections to the sensor element can be minimized. The IDE contacts of the measuring electrode 110 are connected via corresponding Meßdurchkontakte 201 with the bottom element 104, also called M ECS sensor plane. By way of example, the bottom element 104 in FIG. 2 has a significantly larger one

Base surface as the lid member 102 on.

The filter region 106 has, for example, twelve gas-permeable pores 108, which are arranged in four columns and three rows. According to this

Embodiment, the measuring electrode 110 extends at three each other

adjacent sides of the filter area 106. The interdigitated contact structure of the measuring electrode 110 is schematically indicated by three wires running side by side. The heating element 112 forms one except for one

Access opening 202 almost completely closed frame around the

Measuring electrode 110 and the filter portion 106th FIG. 2 also shows a possible contact assignment of connection contacts of the floor element 104. In this case, a back contact 204 for contacting a ground terminal of the sensor element, a first heater contact 206 for contacting a common supply voltage terminal of the two heating elements, a front side contact 208 for contacting a signal output of the sensor element, a second heater contact 210 for

Contacting a common ground terminal of the two heating elements, a first IDE contact 212 for contacting a

Supply voltage terminal of the measuring electrode 110 and a second IDE contact 214 for contacting a ground terminal of the measuring electrode 110th

The bottom element 104 is embodied, for example, as a sensor wafer with two circuit board levels as electrodes, a YSZ membrane as electrode layer (YSZ = yttria-stabilized zirconia, "yttria-stabilized zirconia") and four contact pads for electrical contacting of the sensor 100.

FIGS. 3a to 3d show cross-sectional representations of a cover element 102 of a sensor according to an exemplary embodiment of the present invention

Invention in different stages of production. The cover element 102 is, for example, a reference to FIGS. 1 and 2

described cover element. FIGS. 3a to 3d show a possible process flow for producing a porous, heatable cover element 102 in the form of a protective cap with a measuring electrode 110 with interdigital

Contact structure for measuring a soot load for a

microelectrochemical sensor.

In a first production step of the cover element 102 shown in FIG. 3 a, a silicon wafer is first provided.

In a further production step shown in FIG. 3b, the insulation layer 119, a platinum heater as heating element 112, and the measuring electrode 110 with an interdigital contact structure, also called IDE structure, are applied to the silicon wafer of the cover element 102. In a next step, which is shown in FIG. 3c, the cover element 102 in the filter region 106 is thinned like a cap to obtain the cover recess 116.

Finally, pores 108 are formed to filter the particles, as shown in FIG. 3c.

The cap wafer 102 produced in this way can now be connected to a sensor wafer as a bottom element via wafer bonding in order to obtain the sensor described with reference to FIGS. 1 and 2.

A sensor surface of the sensor element, d. H. an active electrode area is, for example, between ten and several hundred microns in size. Therefore, it is important to avoid any deposition of gas-blocking solids on the

Sensor surface to prevent, such as using a porous protective cap made of silicon, as shown in Fig. 3d.

The heating element 112 and the measuring electrode 110 should be exhaust and

be temperature resistant and can therefore be made of platinum, a platinum-rhodium alloy or gold. As already stated, the sensor with an electrical insulation layer 119 for electrical insulation of

Heating element 112 and measuring electrode 110 from the semiconducting silicon substrate, d. H. from the cover element 102, be executed. The insulating layer 119 is formed by, for example, thermal oxidation or PECVD deposition (plasma-enhanced chemical vapor deposition;

For depositing a metal layer, methods such as sputtering or atomic layer deposition (abbreviated to ALD) can be used, and for the definition of a structure, shadow masks or lithographic masks may be used

Procedure can be used.

As an alternative to the aforementioned deposition and structuring methods, it is possible for the heater structures of the heating element 112 to be screen-printed

noble metal-containing pastes on the cap wafer 102 to produce. To get the necessary heating power to reach the necessary Rußabbrandtemperatur of at least 800 ° C to minimize the effort to produce the gas-permeable pores 108 and to allow the final connection of cap wafer 102 and sensor element, the

Cap wafer 102 thinned in the range of a heated and gas-permeable surface.

Following the thinning, the pores 108 are etched to remove the

Cap wafer 102 to make gas permeable and a certain

To achieve particle filter effect. The pores 108 are produced, for example, by reactive ion deep etching (English: deep reactive ion etching, DRI E for short) or wet-chemical KOH etching of previously, for example lithographically, defined pores. Alternatively, the pores 108 may be created by laser drilling.

After completion of the cap wafer 102, it is connected to the sensor wafer via a suitable bonding process. For long-term and

Temperature-stable wafer-wafer connections are suitable, for example, for anodic silicon-silicon bonding. In order to simplify the interconnection of the cap wafer heating electrode 112 with the remainder of the sensor element and to avoid the use of bonding wires, the cap wafer heating electrode 112 can be connected to a metal layer plane on the sensor wafer via silicon via contacts as an alternative to conventional wire bonding.

If partial pore clogging over the service life can not be ruled out despite active heating of the porous cap wafer 102, it is possible to increase the heated, porous surface of the cap wafer 102 in such a way that a sufficient amount of material remains until the end of the service life

Gas permeability is ensured. A maximum cap size may vary from the requirements of sensor dynamics and in terms of sensor dynamics

Production costs and the construction and connection technology maximum acceptable chip area of the sensor element depend.

According to one embodiment, the contacts for

Cap wafer heater and sensor heater on the chip side connected. This allows the number of sensor contacts through the heated Cap wafer filter and thus the number of costly cable connections are kept small to the outside.

Depending on the embodiment, the connection of sensor and cap heaters can be carried out in series or in parallel connection. The contacts for the

Measuring electrode 110 can also be connected to the MECS sensor plane 104 via silicon through contacts. A distance within the interdigital structure of the measuring electrode 110 should be as low as possible in order to ensure a high sensitivity at low supply voltage.

For integration of soot particle protection function and soot particle measurement, the surface of the protective cap 102 is divided into a porous filter region 106 and a flat surface unstructured region. The filter area 106 is arranged, for example, directly above the sensor element. On the unstructured area, the measuring electrode 110 is arranged. To that

Dead volume over the sensor element, such as a MECS chip to keep small, the measuring electrode 110 may be arranged in ring or frame shape around the filter region 106. 4 shows a schematic cross-sectional view of a floor element

104 of a sensor according to an embodiment of the present

Invention. The bottom element 104, which forms the basic structure of a sensor element described above as the carrier substrate, corresponds in the

Substantially the bottom element shown in Fig. 1, with the difference that the first electrode 124, as shown schematically in Fig. 1, on the

Floor element 104 rests to cover the bottom recess 120, but is integrated into the bottom member 104 such that the first electrode 124, the chamber 130 completely lined to a bottom surface. In addition, the cavern 130 has a direction in the direction of the electrolyte layer 122

tapered cross-section on.

According to this exemplary embodiment, the chamber 130 is realized as a pumping cell in order to pump oxygen through the electrolyte layer 122 by means of the electrolyte 128 realized as a solid electrolyte membrane. Depending on the direction of the voltage applied to the two electrodes 124, 126, oxygen can enter the Chamber 130 in or out of the chamber 130 are pumped out. A pumping direction is shown by way of example with an arrow.

FIG. 5 shows a schematic representation of an internal combustion engine 500 with a previously described sensor 100 in accordance with FIG

Embodiment of the present invention. The sensor 100 is used to determine a concentration of a gas as well as particles in an exhaust gas of the internal combustion engine 500. For this purpose, the sensor 100 is

arranged for example in an exhaust pipe of the internal combustion engine 500. Furthermore, the sensor 100 is designed to be corresponding

Measuring signals 501 to a control unit 502 for controlling the

Internal combustion engine 500 to transmit. The controller 502 may be configured to enter using the measurement signals 501

Combustion air ratio of the internal combustion engine 500, too

Lambda value, so adjusted that pollutant emissions by the

Internal combustion engine 500 is minimized.

6 shows a flowchart of a method 600 for producing a sensor according to an embodiment of the present invention. The method 600 comprises a step 602 in which a composite is formed from a base element, a cover element, a measuring electrode and a heating element. In this case, the bottom element has a sensor element for determining a gas concentration in an exhaust gas of an internal combustion engine. The cover element has in a filter region a plurality of pores, which serve to filter out particles from the exhaust gas. In step 602, the

Cover element connected to the bottom element such that the

Sensor element is covered by the cover element. In this way, an attachment of the particles to the sensor element is prevented. The sensor element is fluidically coupled to an external environment of the sensor via the pores in the filter region. Further, in step 602, the measuring electrode and the

Heating element disposed on the lid member, wherein the measuring electrode is formed to determine a concentration of the particles in the exhaust gas. Depending on the embodiment, the heating element is designed to heat either the filter region or the measuring electrode or both the filter region and the measuring electrode for regeneration. In an optional method step, which precedes step 602, depending on the embodiment, the cover element, the measuring electrode, the heating element or the bottom element can be provided. Accordingly, in step 602, the composite may be formed from either the bottom element, the

Cover element, the measuring electrode and the heating element or from the

Floor element by applying the lid member, the measuring electrode and the heating element or from the bottom element and the lid member by applying the measuring electrode and the heating element or from the

Floor element, the cover element and the measuring electrode are formed by applying the heating element or from the bottom element, the cover element and the heating element by applying the measuring electrode.

FIG. 7 shows a block diagram of an apparatus 700 for carrying out a manufacturing method according to an embodiment of the present invention. The device 700 for producing a sensor for analyzing an exhaust gas of an internal combustion engine is designed, for example, to carry out a method according to FIG. 6. For this purpose, the device 700 comprises a unit 702, which is designed to produce a unit 702 based on FIG. 6

described method step 602 of forming a composite.

The embodiments described and shown in the figures are chosen only by way of example. Different embodiments may be combined together or in relation to individual features. Also, an embodiment can be supplemented by features of another embodiment.

Furthermore, the method steps presented here can be repeated as well as executed in a sequence other than that described.

If an exemplary embodiment comprises an "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

Claims

claims

A sensor (100) for analyzing an exhaust gas of a

Internal combustion engine (500), the sensor (100) comprising: a lid member (102) having a plurality of pores (108) in a filter section (106) for filtering out particulates from the exhaust gas; a measuring electrode (110) disposed on the lid member (102) for determining a particulate concentration in the exhaust gas; a heating element (112) disposed on the lid member (102) for heating the filter portion (106) and / or the measuring electrode (110); and a bottom member (104) having at least one sensor element (118) for determining a gas concentration in the exhaust gas, the cover member (102) covering the sensor element (118) to prevent adsorption of the particles to the sensor element (118). and wherein the sensor element (118) is fluidically coupled to an external environment of the sensor (100) via the filter region (106).

2. Sensor (100) according to claim 1, characterized in that the

Filter region (106) of the sensor element (118) is arranged opposite.

3. Sensor (100) according to one of the preceding claims, characterized in that the measuring electrode (110) and / or the Heating element (112) at least partially framing the filter area (106), in particular encloses except for an access opening (202).

Sensor (100) according to one of the preceding claims, characterized in that the measuring electrode (110) is designed as an interdigital electrode.

Sensor (100) according to one of the preceding claims, characterized in that the cover element (102) at least in

Filter region (106) has a Deckelausnehmung (116), wherein the sensor element (118) of the Deckelausnehmung (116) is arranged opposite.

Sensor (100) according to one of the preceding claims, characterized in that the sensor element (118) has a

Bottom recess (120) in the bottom element (104) and a

Electrolyte layer (122) comprising a first electrode (124), a second electrode (126) and an electrolyte (128) arranged between the first electrode (124) and the second electrode (126), wherein the electrolyte layer (122) forms the bottom recess (12). 120) to a chamber (130) for receiving a reference gas or

Form reference gas mixture, wherein the first electrode (124) with the reference gas or reference gas mixture and the second electrode (126) via the filter region (106) can be acted upon with the exhaust gas.

Sensor (100) according to claim 6, characterized by a further heating element for heating the electrolyte layer (122), in particular wherein the further heating element and the heating element (112) are connected to each other in series and / or in parallel.

Sensor (100) according to one of the preceding claims, characterized in that the cover element (102) and / or the

Floor element (104) is made of a semiconductor material. Internal combustion engine (500) with a sensor (100) according to one of the preceding claims.

A method (600) for producing a sensor (100) for analyzing an exhaust gas of an internal combustion engine (500), the method (600) comprising the following step:

Forming (602) a composite of a bottom element (104), the at least one sensor element (118) for determining a

Gas concentration in the exhaust gas, a cover member (102) having a plurality of pores (108) in a filter region (106) for filtering out particulates from the exhaust gas, a

Measuring electrode (110) for determining a particle concentration in the exhaust gas and a heating element (112) for heating the filter region (106) and / or the measuring electrode (110), wherein the measuring electrode (110) and the heating element (112) on the cover element (102 ), wherein the cover member (102) covers the sensor element (118) to prevent the particles from attaching to the sensor element (118), and wherein the sensor element (118) overlies the sensor element (118)

Filter region (106) is fluidically coupled to an external environment of the sensor (100).

Apparatus (700) adapted to perform all the steps of a method (600) according to claim 10.

A computer program adapted to perform all the steps of a method (600) according to any one of the preceding claims.

A machine-readable storage medium having a computer program stored thereon according to claim 12.