DE102015220855A1 - Sensor device for detecting at least one flow characteristic of a fluid medium - Google Patents

Abstract

A sensor device (10) for detecting at least one flow property of a fluid medium is proposed. The sensor device (10) comprises a sensor housing (14). The sensor housing (14) comprises at least one electronics compartment (20). At least one electronic module (30) with at least one flow sensor (40) for detecting the flow characteristic is accommodated in the electronics compartment (20). Within the sensor housing (14) at least one temperature sensor (44) for detecting a temperature of the fluid medium is further included. The sensor housing (14) also has a plug region (48). Plug-in area conductor tracks (50) for electrically connecting the electronic module (30) are accommodated in the plug area (48). The electronic module (30) is electrically connected to the temperature sensor (44) by means of temperature sensor printed conductors (52). The temperature sensor conductor tracks (52) are at least partially arranged one above the other and / or the connector area conductor tracks (50) each have a first connection section (54) which assigns the electronics module (30) have the temperature sensor conductor tracks (52) one each second connecting portion (56), which assigns to the electronic module (30), wherein the first connecting portion (54) and the second connecting portion (56) extend parallel to each other, wherein the second connecting portion (56) is shorter than the first connecting portion (54) ,

Description

State of the art

Numerous methods and devices for determining flow properties of fluid media, ie liquids and / or gases, are known from the prior art. In principle, the flow properties can be any physically and / or chemically measurable properties which qualify or quantify a flow of the fluid medium. In particular, this may be a flow velocity and / or a mass flow and / or a volume flow.

The invention will be described in more detail below with reference to so-called hot film air mass meter, as for example Konrad Reif (ed.), Sensors in the motor vehicle, 1st edition 2010, pages 146-148 are described. Such Heißfiluuftmassenmesser are usually based on a sensor chip, in particular a silicon sensor chip, with a measuring surface, which is overflowed by the flowing fluid medium. The sensor chip usually comprises at least one heating element and at least two temperature sensors, which are arranged, for example, on the measuring surface of the sensor chip. From an asymmetry of the temperature profile detected by the temperature sensors, which is influenced by the flow of the fluid medium, it is possible to deduce a mass flow and / or volume flow of the fluid medium. Heißfileinuftmassenmesser are usually designed as plug-in sensor, which is fixed or interchangeable introduced into a flow tube.

For example, this flow tube may be an intake tract of an internal combustion engine.

In order to be able to precisely deduce from the sensor signals of the hot-film air mass meter certain flow properties of the fluid medium, it is in many cases desirable to be able to provide further information about the fluid medium. For example, in the DE 10 2012 200 147 A1 a sensor device for detecting at least one flow characteristic of a fluid medium, which additionally comprises a temperature sensor for detecting a temperature of the fluid medium.

Despite the advantages provided by such sensor devices, there is still room for improvement. Thus, the electronic module usually has an evaluation, which is also connected to the temperature sensor, for example via a conductor comb and bonds. Electromagnetic irradiation causes the temperature sensor to heat up and, as a result, deviate from the temperature signal.

Disclosure of the invention

Accordingly, a sensor device for detecting at least one flow characteristic of a flowing fluid medium is proposed, which at least largely avoids the above-described disadvantages of known sensor devices and whose temperature signals are in particular insensitive to electromagnetic radiation and at the same time can be produced inexpensively.

With respect to the at least one flow characteristic to be detected, which can be detected qualitatively and / or quantitatively, reference may be made, for example, to the above description of the prior art. In particular, this flow property may be a flow velocity and / or a mass flow and / or a volume flow of the fluid medium. The fluid medium may in particular be a gas, preferably air. The sensor device can be used in particular in motor vehicle technology, for example in the intake tract of an internal combustion engine. However, other applications are possible in principle.

The sensor device comprises at least one sensor housing. In the context of the present invention, a sensor housing is to be understood as meaning a one-part or multi-part device which at least largely seals the sensor device to the outside and at least largely protects it against mechanical effects and preferably also other types of actions, for example chemical effects and / or moisture. In particular, the sensor housing may comprise at least one plug-in sensor or be configured as a plug-in sensor, wherein the plug-in sensor can be introduced into the flowing fluid medium, wherein an exchangeable or a permanent introduction is conceivable. The plug-in sensor can protrude, for example, into a flow tube of the flowing fluid medium, wherein the flow tube itself can be part of the sensor device or can also be provided as a separate component, for example with an opening into which the plug-in sensor can be inserted. The plug-in sensor and the flow housing may in particular be made at least partially of a plastic material, for example by means of an injection molding process.

In the sensor housing is at least one electronic module with at least one flow sensor for detecting the flow characteristic added. A receptacle in the sensor housing is to be understood that the electronic module is at least partially, preferably completely, to be enclosed by the sensor housing. In particular, as will be explained in more detail below, the electronic module can be arranged in an electronics compartment of the sensor housing, which can be designed, for example, as a cavity in the sensor housing and which can preferably be made lockable by at least one electronics compartment cover or another closure device.

Under a flow sensor is basically any sensor element to understand, which is configured to detect the at least one flow characteristic. In particular, the flow sensor may be at least one hot-film air mass meter chip, for example of the type described above. In particular, this hot-film air mass sensor chip may comprise at least one silicon chip with a measurement surface which can be overflowed by the flowing fluid medium. For example, at least one heating element and at least two temperature sensors can be located on this sensor surface, it being possible, as described above, to be able to be closed to the at least one flow property from an asymmetry of the temperature profile measured by means of the temperature sensor. The at least one flow sensor can be arranged, for example, on a sensor carrier of the electronic module, which protrudes into the flowing fluid medium.

In particular, the electronic module can be designed in one piece and can in particular carry a control and / or evaluation circuit which is set up to control the flow sensor and / or to receive signals from the flow sensor. Accordingly, the electronic module may for example comprise at least one circuit carrier. Furthermore, the electronic module can in particular have the at least one sensor carrier, which is preferably mechanically connected to the circuit carrier. For example, the circuit carrier can be arranged in an electronics compartment of the sensor housing and the sensor carrier can protrude out of this electronics compartment into the fluid medium. It is particularly preferred if the sensor housing has at least one channel through which the fluid medium can flow, the sensor carrier of the electronic module carrying the flow sensor projecting from the electronics compartment into the channel through which the fluid medium can flow in the sensor housing. This at least one channel may in particular be designed in one piece, but may also have at least one main channel and at least one bypass channel branching off from this main channel, the sensor carrier preferably protruding into the bypass channel, as is generally known from the prior art.

The circuit carrier of the electronic module may in particular comprise a printed circuit board, which is used alone or which is for example also mounted on a mechanical support, for example a stamped and bent part, for example of a metallic material. The sensor carrier can be connected directly to the circuit carrier or else to the carrier part, for example in the stamped and bent part, for example by the sensor carrier being molded onto this stamped and bent part. Other configurations are possible in principle. Thus, it is conceivable, for example, to produce the electronic module from a printed circuit board material, wherein both the circuit carrier and the sensor carrier are made of the printed circuit board material, preferably from a piece of printed circuit board material. Again alternatively or additionally, it is also possible to use known from the prior art injection molded circuit boards as an electronic module, such as injection molded circuit boards in one or more so-called MID techniques (MID = molded interconnect device). Various embodiments are conceivable.

The sensor housing further has a connector area. In this case, a plug region is understood to mean the region of the sensor housing which is designed to be connected or contacted with an electrical plug. For this purpose, plug-in area conductor tracks, which are designed, for example, as plug pins, are accommodated for the electrical connection of the electronic module in the plug area.

The sensor device furthermore has a temperature sensor, in particular at least one temperature sensor arranged on an outer side of the sensor housing. The temperature sensor may be arranged in at least one recess on a side wall of the sensor housing. The temperature sensor may in particular comprise at least one temperature-dependent resistor. Alternatively or additionally, other types of temperature sensors can be used. In particular, the temperature sensor can be overflowed freely by the flowing fluid medium, ie not be enclosed by the sensor housing of the sensor element. The temperature sensor can be connected in particular by a frictional connection and / or positive connection with the sensor housing, for example by caulking leads of the temperature sensor with an outer wall of the sensor housing or connected in any other way. Supply lines of the temperature sensor can in particular into the interior be guided into the sensor housing and be connected there, for example, to the electronic module and / or be connected to a connector of the sensor device. Various other embodiments are conceivable in principle.

The electronic module furthermore has temperature sensor printed conductors, by means of which the electronic module is electrically connected to the temperature sensor. The temperature sensor conductor tracks can be arranged at least partially one above the other. Thus, the temperature sensor trace is the main influence on the electromagnetic compatibility of the temperature signal. These span a surface. The size of this area is relevant for the coupling of the interference caused by electromagnetic radiation and thus for the current generated in the temperature sensor tracks. This induced current leads to a heating of the temperature sensor. Due to the fact that the temperature sensor printed conductors are arranged according to the invention at least partially above one another, this spanned surface is minimized, so that the interference caused by electromagnetic radiation is reduced.

Alternatively or additionally, the connector area conductor tracks each have a first connection portion, which assigns the electronics module and can be electrically connected to the electronic module, for example by means of bonding wires. The temperature sensor printed conductors may alternatively or additionally each have a second connecting portion, which assigns the electronic module and is electrically connected thereto by means of, for example, bonding wires. The first connection portion and the second connection portion may extend parallel to each other. It is provided that the second connecting portion is shorter than the first connecting portion. The length or shortness of the second connecting portion or first connecting portion is determined in the parallel extension direction. So it comes in the vicinity of the bond pads of the electronic module to a parallel arrangement of the conductor ridges of the plug and the temperature sensor. Electromagnetic irradiation leads to overcoupling of interference from the plug-in conductor tracks to the temperature sensor tracks. By the shortest possible parallel Leiterkammführung the overcoupling of the fault can be avoided.

The first connection section of one of the connector area conductor tracks and the second connection section of one of the temperature sensor conductor tracks may be arranged adjacent to one another. A distance of the first connection portion of this one connector area conductor track to the second connection portion of said one temperature sensor conductor track may be greater than a distance of the connector area conductor track and / or the temperature sensor conductor track from one another. Due to a larger distance between the connector area interconnects, the coupling of the disturbance can be avoided. The connector portion may be separated from the electronics compartment by a wall, the connector portion trace having the first connection portion and the temperature sensing trace having the second connection portion penetrating the wall. The electronics module may have a bottom plate. The bottom plate may be made of an electrically conductive material, such as metal, wherein the bottom plate and the temperature sensing conductor tracks are at least partially arranged one above the other. In other words, the bottom plate and the temperature sensor traces at least partially overlap in a projected to a common plane. The bottom plate can be connected to a fixed reference potential, such as the sensor ground.

The sensor housing may, as mentioned above, have an electronics compartment lid. The electronics compartment lid can be designed to close the electronics compartment. The electronics compartment lid may be at least partially made of an electrically conductive material. For example, the electronics compartment lid is made of an electrically conductive plastic. The electrical conductivity can also be produced by inserting a metal plate in the electronics compartment lid. The electronics compartment cover and the temperature sensor conductor tracks can be arranged at least partially one above the other. In other words, the electronics compartment lid and the temperature sensor traces partially overlap, provided they are projected onto a common plane. The electronics compartment lid may be connected to a fixed reference potential, such as the sensor ground. The temperature sensor is preferably arranged outside the electronics compartment.

Brief description of the drawings

Further optional details and features of the invention will become apparent from the following description of preferred embodiments, which are shown schematically in the figures.

Show it:

1 an exploded view of a sensor device according to the invention for detecting at least one flow characteristic of a fluid medium,

2 a plan view of conductor tracks according to a first embodiment,

3 a perspective view of conductor tracks according to a second embodiment,

4 a perspective view of conductor tracks according to a third embodiment,

5 a top view of an electronic module according to a fourth embodiment,

6 a bottom view of the electronic module of the fourth embodiment and

7 a perspective view of an electronic module according to a fifth embodiment.

Embodiments of the invention

1 shows an exploded view of a sensor device according to the invention 10 for detecting at least one flow characteristic of a fluid medium. The sensor device 10 is designed in this embodiment as Heißfiluuftmassenmesser and includes a plug-in sensor 12 which can be introduced into a flow of a fluid medium, for example an intake air mass, for example reversibly inserted into a suction pipe or permanently installed. The sensor device comprises a sensor housing 14 , Inside the sensor housing 14 are a channel area 16 and an electronics area 18 with one in the sensor housing 14 taken in electronics room 20 added. The channel area 16 is from a bypass duct cover 22 closable. In the bypass duct cover 22 is a channel through which the fluid medium can flow 24 educated. The channel 24 again has a main channel 26 and a bypass channel branching from this 28 on. In the electronics room 20 is an electronic module 30 taken, which is a circuit carrier 32 with a control and / or evaluation circuit 34 includes, for example, on a floor panel 36 can be included. Furthermore, the electronic module includes 30 a sensor carrier 38 in the form of a to the floor panel 36 molded wing, which in the bypass channel 28 protrudes. In the sensor carrier 38 is a flow sensor 40 embedded in the form of a Heißfileinuftmassenmesserchips. The sensor carrier 38 and the floor panel 36 thus form a unit of the electronic module 30 , In addition to the flow sensor 40 is still the electronics of the circuit board 32 and the control and / or evaluation circuit 34 on the floor panel 36 glued. The flow sensor 40 and the control and / or evaluation circuit 34 are usually connected by bond connections. The resulting electronic module 30 For example, in the electronics room 20 glued and the entire plug-in sensor 12 is through an electronics compartment lid 42 locked.

The sensor device 10 also has a temperature sensor 44 on. The temperature sensor is designed to detect a temperature of the fluid medium and based on the representation of 1 on a bottom 46 of the sensor housing 12 arranged. The temperature sensor 44 is inside the sensor housing 14 absorbed, but the fluid medium exposable. The sensor housing 14 also has a connector area 48 on. The connector area 48 is designed for electrical contact by means of a connector not shown in detail. The connector area 48 is located in a channel 24 opposite side of the electronics compartment 20 adjacent to this. The connector area 48 is electrically contacted by means of the plug, for example a control device.

2 shows a perspective view of an arrangement of conductor tracks according to a first embodiment. Shown are connector area conductor tracks 50 in the connector area 48 which is used to electrically connect the electronics module 30 are included therein. Also shown are temperature sensor tracks 52 , The electronics module 30 is with the temperature sensor 44 by means of temperature sensor tracks 52 electrically connected. The connector area traces 50 each have a first connecting portion 54 on, the electronics module 30 assigns. The temperature sensor tracks 52 have a second connecting portion 56 on, the electronics module 30 assigns. The first connection section 54 and the second connection portion 56 extend parallel to each other. The temperature sensor tracks 52 each have a temperature sensor 44 facing section 58 to which the temperature sensor tracks with the temperature sensor 44 connected, and a middle section 60 on. The middle section 60 is located between the second connection section 56 and the temperature sensor 44 facing section 58 , In the conductor tracks of the first embodiment, the temperature sensor tracks are 52 at least partially arranged one above the other. More specifically, the temperature sensor traces are in the middle section 60 at least partially arranged one above the other.

3 shows an arrangement of conductor tracks according to a second embodiment. Hereinafter, only the differences from the previous embodiment will be described and the same components are given the same reference numerals. In the conductor tracks of the second embodiment, the second connection portion 56 shorter than the first connection section 54 , Preference is given to the parallel extension of the first connecting portion 54 and the second connection portion 56 to realize as short as technically possible, ie the second connecting section 56 is designed as short as technically possible. The second connection section 56 should be designed as short as technically possible. The minimum length of the second connection section 56 results from the necessary dimensions to the control and / or evaluation circuit 34 by means of bonding wire with the temperature sensor conductor tracks 52 connect to.

4 shows a perspective view of an arrangement of conductor tracks according to a third embodiment. Hereinafter, only the differences from the previous embodiments will be described and the same components are given the same reference numerals. As in 4 can be seen, the first connecting portion 54 one of the connector area traces 50 and the second connection portion 56 one of the temperature sensor tracks 52 an adjacent arrangement to each other. A distance 62 between the first connection section 54 this one connector area trace 50 to the second connecting portion 56 This temperature sensor trace is greater than a distance of the connector area trace 50 and / or the temperature sensor trace 52 to each other. Compared to conventional sensor device are the temperature sensor tracks 52 thus further away from the connector area conductor tracks 50 spaced.

5 shows a perspective view of an electronic module 30 according to a fourth embodiment. Hereinafter, only the differences from the previous embodiments will be described and the same components are given the same reference numerals. The fourth embodiment realizes further improvement of electromagnetic compatibility. The floor panel 36 is made of an electrically conductive material, such as metal. The floor panel 36 and the temperature sensor traces 52 are at least partially arranged one above the other.

6 shows a bottom view of the electronic module 30 the fourth embodiment. The overlapping of the temperature sensor printed conductors can be seen 52 and the floor panel 36 , This will cause the temperature sensor traces 52 shielded. The floor panel 36 is there with a fixed reference potential 64 connected, such as the sensor ground.

7 shows a perspective view of an electronic module 30 according to a fifth embodiment. Hereinafter, only the differences from the previous embodiments will be described and the same components are given the same reference numerals. A shield as in the fourth embodiment may similarly be realized by the electronics compartment lid 42 at least partially made of an electrically conductive material, such as an electrically conductive plastic, and the electronics compartment lid 42 and the temperature sensor traces 52 at least partially arranged one above the other. This will cause the temperature sensor traces 52 shielded. Again, the electronics compartment lid 42 with the fixed reference potential 64 , such as the sensor mass connected.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012200147 A1 [0004]

Cited non-patent literature

• Konrad Reif (ed.), Sensors in the motor vehicle, 1st edition 2010, pages 146-148 [0002]

Claims (10)

Sensor device ( 10 ) for detecting at least one flow characteristic of a fluid medium, comprising a sensor housing ( 14 ), wherein the sensor housing ( 14 ) at least one electronics room ( 20 ), wherein in the electronics room ( 20 ) at least one electronic module ( 30 ) with at least one flow sensor ( 40 ) is recorded for detecting the flow characteristic, wherein further within the sensor housing ( 14 ) at least one temperature sensor ( 44 ) is recorded for detecting a temperature of the fluid medium, wherein the sensor housing ( 14 ) continue to have a connector area ( 48 ), wherein in the connector area ( 48 ) Connector area interconnects ( 50 ) for electrically connecting the electronic module ( 30 ), the electronic module ( 30 ) by means of temperature sensor tracks ( 52 ) with the temperature sensor ( 44 ) is electrically connected, characterized in that the temperature sensor tracks ( 52 ) are arranged at least partially one above the other and / or the connector area conductor tracks ( 50 ) each have a first connection section ( 54 ) provided to the electronic module ( 30 ), the temperature sensor tracks ( 52 ) each have a second connecting portion ( 56 ) provided to the electronic module ( 30 ), the first connecting section ( 54 ) and the second connection section ( 56 ) extend parallel to each other, wherein the second connecting portion ( 56 ) shorter than the first connecting section ( 54 ). Sensor device ( 10 ) according to the preceding claim, wherein the first connecting section ( 54 ) one of the plug area interconnects ( 50 ) and the second connection section ( 56 ) one of the temperature sensor tracks ( 52 ) are arranged adjacent to each other, wherein a distance ( 62 ) of the first connection section ( 54 ) of a connector area trace ( 50 ) to the second connection section ( 56 ) of a temperature sensor trace ( 52 ) greater than a distance of the connector area interconnects ( 50 ) and / or the temperature sensor tracks ( 52 ) is to each other. Sensor device ( 10 ) according to one of the preceding claims, wherein the temperature sensor tracks ( 52 ) in each case one the temperature sensor ( 44 ) facing section ( 58 ) and a middle section ( 60 ), wherein the middle section ( 60 ) between the second connecting portion ( 56 ) and the temperature sensor ( 44 ) facing section ( 58 ), wherein the temperature sensor tracks ( 52 ) in the middle section ( 60 ) are at least partially arranged one above the other. Sensor device ( 10 ) according to one of the preceding claims, wherein the connector area ( 48 ) from the electronics room ( 20 ) is separated by a wall, wherein the plug tracks ( 50 ) with the first connecting section ( 54 ) and the temperature sensor tracks ( 52 ) with the second connecting portion ( 56 ) penetrate the wall. Sensor device ( 10 ) according to one of the preceding claims, wherein the electronic module ( 30 ) a floor panel ( 36 ), wherein the bottom plate ( 36 ) is made of an electrically conductive material, wherein the bottom plate ( 36 ) and the temperature sensor tracks ( 52 ) are at least partially arranged one above the other. Sensor device ( 10 ) according to the preceding claim, wherein the floor panel ( 36 ) is connected to a fixed reference potential. Sensor device ( 10 ) according to one of the preceding claims, wherein the sensor housing ( 14 ) an electronics compartment lid ( 42 ), wherein the electronics compartment cover ( 42 ) for closing the electronics compartment ( 20 ), wherein the electronics compartment cover ( 42 ) is at least partially made of an electrically conductive material, wherein the electronics compartment cover ( 42 ) and the temperature sensor tracks ( 52 ) are at least partially arranged one above the other. Sensor device ( 10 ) according to the preceding claim, wherein the electronics compartment cover ( 42 ) is connected to a fixed reference potential. Sensor device ( 10 ) according to any one of the preceding claims, wherein the temperature sensor ( 44 ) outside the electronics room ( 20 ) is arranged. Sensor device ( 10 ) according to one of the preceding claims, wherein the electronic module ( 30 ) a sensor carrier ( 38 ), wherein the sensor carrier ( 38 ) the flow sensor ( 40 ) and from the electronics room ( 20 ) in at least one of the fluid medium flow channel ( 24 ) in the sensor housing ( 14 protrudes.

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