FI3421955T3 - Method of making an electrical sensor, moulded part and electrical sensor with moulded part - Google Patents

Claims (17)

1 17179042.1 METHOD OF MAKING AN ELECTRICAL SENSOR, MOULDED PART AND ELECTRICAL SENSOR WITH MOULDED PART The invention relates to a method for producing an electrical sensor, in particular a temperature sensor, having the features of the generic term of claim 1. Furthermore, the invention relates to an electrical sensor with a moulded part.

The moulded part is therefore a sensor component.

State of the art

EP 0 905 493 Al describes an electrical sensor, in particular a temperature sensor, which has a simple design and is intended to be largely automated.

It comprises a printed circuit board made of an electrically insulating substrate based on temperature-resistant materials, such as epoxy, triazines, polyimides (PI) or fluorides (PTFE). A component in the form of an SMD chip is arranged on the front side of the printed circuit board, which is electrically connected to connection fields of the printed circuit board by means of its contacts.

The electrical connection is made by a fused bond, preferably by soldering.

From the connection fields, conductor tracks arranged on the front and on the back of the printed circuit board lead to connection contact fields, which serve to electrically connect the printed circuit board with the connection conductors of a connection cable.

The electrical connection is also preferably made here by a fusion bond, in particular by soldering.

A contact bushing in the area of the SMD chip electrically connects the rear conductor track to the associated connection field on the front of the printed circuit board.

EP 0 833 550 A2 describes a printed circuit board with at least one component as a measuring resistor, heating resistor or measuring electrode arrangement, as well as a method for its production.

The printed circuit board can be used in particular in a temperature sensor.

Temperature sensors are also described in EP 1 568 978 Al and EP 0 547 750 Al.

Based on the aforementioned state of the art, the present invention is based on the task of simplifying the production of an electrical sensor, in particular a temperature sensor.

A high degree of automation is also to be achieved in production.

In addition, a

2 17179042.1 method is to be specified that enables the production of miniaturized electrical sensors, in particular temperature sensors.

In order achieve the object, the method with the features of claim 1, as well as the electrical sensor with the features of claim 11 are proposed.

Advantageous further embodiments of the invention can be found in the respective dependent claims.

Disclosure of the invention In the proposed method for producing an electrical sensor, in particular a temperature sensor, a carrier element made of plastic is fitted with a wireless measuring resistor in the form of an SMD component which has external electrical connection surfaces, wherein the SMD component is arranged and oriented on the carrier element in such a way that the electrical connection surfaces come to lie on the side facing away from the carrier element.

According to the invention, the carrier element fitted with the measuring resistor is connected to a moulded part made of plastic, so that the measuring resistor is covered and held by the moulded part in areas and the electrical connection surfaces of the measuring resistor are exposed at least in areas.

The measuring resistor is then electrically connected to connecting wires via the electrical connection surfaces which are exposed at least in areas.

The moulded part is used to guide and/or position the connecting wires and the guidance is effected via guide channels formed in the moulded part.

Accordingly, the reguired electrical connection of the measuring resistor is established via connecting wires in the method according to the invention.

These are fed to the measuring resistor and electrically connected to it in the area of exposed electrical connection surfaces of the measuring resistor.

This means that there is no need for a printed circuit board with tracks for contacting the measuring resistor.

Furthermore, connection fields or connection contact fields according to the aforementioned state of the art are not reguired.

The carrier element to be fitted with the measuring resistor can therefore be of comparatively simple design.

At the same time, the number of electrical connections or contact points to be made is reduced.

Conseguently, the production of an electrical sensor, in particular a temperature sensor, can be simplified by applying the method according to the invention.

3 17179042.1

In this context, the term “connecting wire” also includes a stranded wire consisting of several individual wires.

For the sake of simplicity, however, the term “connecting wire” will be used throughout the following to refer to a wire that is to be contacted with an electrical connection surface.

Furthermore, the connecting wire or stranded wire can have an insulating sheath which — at least in the area of the contact to be made — may have to be removed beforehand.

This method step is optional and therefore not mentioned separately.

According to the invention, a wireless measuring resistor in the form of an SMD component is used when carrying out the method according to the invention, so that the production of the electrical sensor can be further simplified.

This is because an SMD component usually has external electrical connection surfaces that are easily accessible and thus easy to contact.

The SMD component is arranged or oriented on the carrier element in such a way that the electrical connection surfaces are located on the side of the measuring resistor facing away from the carrier element.

The connecting wires can then be placed over or on the electrical connection surfaces of the measuring resistor and electrically connected to them, preferably soldered and/or clamped.

Preferably, an SMD device produced in a thin-film technology is used as a wireless measurement resistor.

Such SMD components are particularly small and robust.

For the production of a temperature sensor, a platinum measuring resistor is preferably used.

For example, a platinum chip temperature sensor in SMD design according to DIN EN 60751 can be used.

In particular, this can have the shape of a flat cuboid, which simplifies the assembly of the carrier element with the SMD component.

In the method according to the invention, the carrier element fitted with the measuring resistor is connected to a moulded part made of plastic in such a way that the measuring resistor is covered by the moulded part, but only partially.

This is because the electrical connection surfaces of the measuring resistor must remain free — at least in areas — in order to establish the electrical connection with the connecting wires.

In addition, the measuring resistor can be covered by the moulded part so that protection of the measuring resistor against external influences is achieved.

The fact that the measuring resistor is partially covered by the moulded part also means that the measuring resistor is held on the carrier element.

In addition to its protective function, the moulded part thus also has a holding function or the function of

4 17179042.1 a component holder.

The measuring resistor is preferably located between the carrier element and the moulded part.

Furthermore, the moulded part also fixes the position of the measuring resistor on the carrier element.

By fixing the position, the position of the measuring resistor on the carrier element or the position of the electrical connection surfaces is precisely specified, so that the feeding of the connecting wires to the electrical connection surfaces is simplified.

In particular, the feeding and positioning of the connecting wires can be automated.

Furthermore, fixing the position of the measuring resistor on the carrier element provides strain relief for the electrical connections made.

Advantageously, the moulded part is connected to the carrier element in a force- fitting and/or form-fitting manner.

The force-fitting and/or form-fitting connection can be established by means of a plug-in, press, clamp and/or snap-in connection, for example.

Such connections can be made easily and quickly.

This applies in particular if the force- fitting and/or form-fitting connection is to be produced by means of an automated method.

A form-fitting connection of the moulded part to the carrier element is considered particularly advantageous, since the form-fitting connection secures the position of the moulded part in relation to the carrier element.

The form-fitting connection is thus particularly robust and facilitates handling of the connected components.

For example, a form-fitting connection can be realized by means of a simple plug-in connection.

Furthermore, the measuring resistor is preferably inserted into a recess of the carrier element when the carrier element is fitted.

The recess defines the position of the measuring resistor in relation to the carrier element.

At the same time, it prevents unwanted displacement of the measuring resistor relative to the carrier element.

The shape of the recess is preferably adapted to the shape of the measuring resistor.

A particularly simple shape of the measuring resistor, for example a flat cuboid shape, is advantageous in this case.

Preferably, the measuring resistor is inserted flush with the surface in the recess of the carrier element, so that a flat contact surface is created for the moulded part.

In further development of the invention, it is proposed that the moulded part has at least one further function in addition to the functions already mentioned.

This is because — as shown below — the production of an electrical sensor, in particular a

17179042.1 temperature sensor, can be further simplified by function integration, and in particular the degree of automation can be further increased.

Furthermore, the moulded part is used to guide and/or position the connecting wires when carrying out the method according to the invention.

Guiding is effected via

5 guide channels formed in the moulded part.

These are preferably arranged at a distance from one another and/or running parallel, so that the connecting wires are at the same time electrically insulated by the moulded part.

The moulded part then also has an insulating function.

In order to be able to assume the function of an insulating component, the moulded part is preferably made of an electrically insulating or electrically non-

conductive plastic.

The guiding function of the moulded part facilitates the feeding of the connecting wires to the electrical connection surfaces of the measuring resistor.

To ensure that the ends of the connecting wires come to lie exactly above or on the electrical connection surfaces so that the required electrical connection can be made, the moulded part is preferably also used as a positioning aid.

Thanks to these additional functions of the moulded part, the positioning of the connecting wires can be largely automated.

Preferably, the moulded part has an elongated design, wherein the guide channels for guiding the connecting wires run essentially parallel to the longitudinal extent of the moulded part.

In this way, maximum guide lengths can be achieved.

Furthermore, the carrier element preferably also has an elongated design, wherein the moulded part and the carrier element are aligned in such a way that the guide channels formed in the moulded part run essentially parallel to the longitudinal extent of the moulded part as well as parallel to the longitudinal extent of the carrier element.

In at least one transverse direction to the longitudinal extension of the moulded part or the carrier element, the dimensions can be minimized so that a particularly small-volume electrical sensor is created.

In further development of the method according to the invention, it is further proposed that the connecting wires are electrically connected to the electrical connecting surfaces of the measuring resistor in the area of at least one recess passing through the moulded part.

The at least one recess is such that it forms a kind of window via which the electrical connection of at least one connecting wire to an electrical connecting surface can be established.

Preferably, a recess or window is provided for each connecting wire.

6 17179042.1

The size and/or the position of the at least one recess is or are predetermined by the position of the electrical connection surfaces of the measuring resistor.

This is because the at least one recess formed in the moulded part must be brought into overlap with at least one electrical connection surface of the measuring resistor in order to establish an electrical connection of a connecting wire with an electrical connection surface.

Furthermore, the connecting wire must be positioned in such a way that one end of the connecting wire comes to lie in the area of the recess above or on the electrical connection surface.

The electrical connection can then be established.

The exact position of the electrical connection can thus be specified via the at least one recess formed in the moulded part, so that this method can also be automated.

To ensure that the ends of the connecting wires come to lie in the area of at least one recess above or on the electrical connection surfaces, it is proposed that the guide channels formed in the moulded part for guiding the connecting wires end in a recess.

Preferably, each guide channel ends in a recess assigned to it.

The respective end position of a connecting wire is then specified via a wall surface which bounds the recess and is opposite the guide channel.

If the moulded part is penetrated by several recesses, preferably by two recesses, these are preferably arranged at a distance from one another and/or offset from one another.

The distance between the recesses is preferably measured in the longitudinal direction of the connecting wires or the guide channels formed in the moulded part.

This means that the guide channels are designed to be of differing lengths.

In this way, spatial ordering of the electrical connection points is achieved.

Furthermore, the risk of an electrical short circuit is eliminated or at least minimized.

A distance between the guide channels can be accommodated by offsetting the recesses relative to one another.

In further development of the method according to the invention, it is further proposed that the connecting wires are electrically connected to the electrical connection surfaces of the measuring resistor by soldering and/or clamping.

If the electrical connection is to be made by soldering, the moulded part can be used as a “soldering jig”. The solder for producing the soldered joint is introduced in the area of a recess passing through the moulded part.

The exact position of the soldered joint is thus predetermined by the recess, so that this method step can also be automated.

As an alternative or supplement, the electrical connection can be made by clamping.

Preferably, at least one thrust piece is used for this purpose, which is inserted

7 17179042.1 into a recess of the moulded part and is connected to the moulded part in a force-fitting and/or form-fitting manner, so that at least one connecting wire is pressed against an electrical connecting surface of the measuring resistor.

The required pressure or clamping force can be applied via the force-fitting and/or form-fitting connection of the thrust piece to the moulded part.

The thrust piece may already be connected to the moulded part, for example via a hinge or joint.

In this case, the thrust piece only needs to be swivelled for insertion into the recess of the moulded part.

If several thrust pieces are provided, they can be interconnected so that they can be inserted into the moulded part as a unit.

The connection can be effected, for example, by means of a type of bracket, which at the same time simplifies the handling of the unit comprising several thrust pieces.

The force-fitting and/or form-fitting connection of the at least one thrust piece to the moulded part can be produced in a simple manner by means of a plug-in, press, clamp and/or snap-in connection.

For example, clamp and/or snap-in means can be provided in the area of a recess for receiving a thrust piece, wherein the snap-in means preferably engage behind or around the thrust piece so that a form fit is achieved.

If snap-in means are provided which engage behind or around the thrust piece on two opposite sides, a pressure force can be generated via this which ensures that a connecting wire is pressed evenly against an electrical connecting surface.

Preferably, a recess passing through the moulded part and a thrust piece insertable into the recess are provided for each connecting wire.

Furthermore, each recess preferably also has snap-in means which are arranged on opposite sides and engage behind or around the thrust piece inserted in the recess.

For this purpose, the snap-in means can each be designed in the manner of a spring arm, which has a certain resilience to allow insertion of the thrust piece into the recess.

After insertion, the snap-in means assumes its original shape/position and snaps in behind the thrust piece.

In further development of the method according to the invention, it is further proposed that, after the connecting wires have been electrically connected to the electrical connection surfaces of the measuring resistor, the carrier element, the measuring resistor and/or the moulded part are encapsulated at least in areas with a plastic.

Depending on the specific design of the plastic overmould, the latter forms a protective sheath that protects the measuring resistor from external influences.

At the same time, a seal can be achieved.

An electrical sensor produced in this way is therefore

8 17179042.1 particularly robust and thus versatile.

If the electrical sensor is a temperature sensor, a thermally conductive plastic is preferably used for overmoulding.

In this way, a fast response of the temperature sensor is maintained.

As an alternative or supplement to overmoulding with plastic, the carrier element,

the measuring resistor and the moulded part can be inserted into a housing.

A housing can in particular increase the robustness of the sensor against mechanical impairments and/or against aggressive media.

Advantageously, the method according to the invention is automated in individual steps or in all of its steps.

Production costs can be reduced by means of a high degree of automation.

The method according to the invention is preferably carried out in an automatic placement machine.

The moulded part used in carrying out the method can assume the function of a component holder, a guide element, a positioning aid, an insulating component and/or a soldering jig.

In the method according to the invention, a carrier element and/or a moulded part made of an electrically insulating and thermally conductive plastic is or are preferably used.

This applies in particular if the method is used to produce a temperature sensor.

The use of a thermally conductive plastic ensures a fast response and a high degree of measuring accuracy of the temperature sensor.

In order to achieve the object mentioned at the beginning, an electrical sensor, in particular a temperature sensor, with a moulded part is also proposed.

The moulded part is characterized in that it

- is made of plastic, in particular of an electrically insulating and thermally conductive plastic,

- is penetrated by at least one recess,

- has at least one guide channel, which preferably ends in a recess passing through the moulded part,

- and has connecting means for the force-fitting and/or form-fitting connection to a carrier element, and wherein a connecting wire is inserted in the at least one guide channel of the moulded part, which is electrically connected, preferably soldered and/or clamped, in the area of the recess to an electrical connecting surface of the measuring resistor.

The moulded part thus has all the features that enable the moulded part to be used in the method according to the invention described above.

9 17179042.1

According to the invention, the moulded part is connected via the connecting means to a carrier element which has previously been equipped with a measuring resistor, preferably in the form of an SMD component.

The moulded part is then used as a component holder.

A connecting wire is fed to the measuring resistor via the at least one guide channel formed in the moulded part and then electrically connected, in particular soldered and/or clamped, to the electrical connecting surface of the measuring resistor in the area of the recess.

Accordingly, the moulded part can further be used as a guide element, a positioning aid and/or a soldering gage.

In the design as a plastic part, the moulded part can also be produced easily and inexpensively.

If an electrically insulating and thermally conductive plastic is used, the moulded part can also be used as an insulating component.

The connecting means for connecting the moulded part to the carrier element preferably comprise at least two pin-shaped connecting means which can be inserted into correspondingly designed recesses in the carrier element.

The pin-shaped connecting means engaging in the recesses can be used to achieve a form fit that prevents displacement of the moulded part relative to the carrier element.

The fact that at least two pin-shaped connecting means are provided also prevents the moulded part from rotating.

Furthermore, the connecting means are preferably arranged on a support surface of the moulded part, via which the moulded part can be supported on the carrier element.

By supporting the moulded part on the carrier element, the position of the measuring resistor on the carrier element can be fixed at the same time.

Further preferably, the moulded part has at least two recesses extending through the moulded part.

The recesses ensure that, after the moulded part has been connected to the carrier element, the electrical connection surfaces of a measuring resistor arranged on the carrier element are exposed at least in areas.

For this purpose, the recesses are preferably arranged at a distance from one another and/or offset from one another.

Each recess can thus be assigned to an electrical connection surface of the measuring resistor or a connecting wire.

Furthermore, an electrical connection of a connecting wire with an electrical connection surface of the measuring resistor can be established in the area of a recess.

Advantageously, the moulded part has an elongated shape.

The elongated shape favours the formation of a distance between the recesses passing through the moulded part.

Furthermore, the moulded part preferably has a flat design, wherein the recesses

10 17179042.1 pass through the moulded part in the direction of its smallest dimension.

The recesses thus form windows which ensure accessibility to the electrical connection surfaces of the measuring resistor in order to be able to make the required electrical connection.

Furthermore, at least two guide channels are preferably provided, which are arranged at a distance from one another and/or running parallel.

Each guide channel can be used to guide and/or position a connecting wires.

The distance between the guide channels can also provide electrical insulation for the connecting wires.

It is further proposed that each guide channel terminates in a recess passing through the moulded part.

The end position of a connecting wire can thus be pre-set via the recess.

This ensures that the end of a connecting wire comes to lie exactly over or on an electrical terminal area of the sensing resistor to make the required electrical connection.

The guide channels preferably run parallel to the longitudinal extension of the moulded part, so that long guide lengths can be achieved.

The recesses which pass through the moulded part and in which the guide channels end are preferably guided perpendicularly thereto.

Furthermore, the recesses are preferably arranged one behind the other at a distance from one another or in the longitudinal direction of the guide channels, so that the guide channels ending in these recesses are of differing lengths.

In this way, a spatial ordering of the electrical connection points is achieved.

The electrical connection can be made in particular by soldering and/or clamping.

The clamping force required for clamping can be applied via at least one thrust piece, which is preferably inserted into a recess in the moulded part and connected to the moulded part in a force-fitting and/or a form-fitting manner.

In further development of the invention, it is therefore proposed that the moulded part has connecting means for the force-fitting and/or form-fitting connection to at least one thrust piece.

Preferably, the number of thrust pieces corresponds to the number of connecting wires, so that each connecting wire (or stranded wire) can be clamped separately.

Furthermore, the connecting means provided for the force-fitting and/or form-fitting connection with the thrust piece are preferably arranged in the area of at least one recess passing through the moulded part.

The thrust piece can then be inserted into the recess and connected to the moulded part in a force-fitting and/or a form-fitting manner when inserted into the recess.

Preferably, a plug-in, press, clamp and/or snap-in connection is made via the connecting means.

To realize a snap-in connection, the

11 17179042.1 connecting means preferably have snap-in means which engage behind or around the thrust piece inserted in the recess.

This ensures that a pressure or clamping force applied to a connecting wire via the thrust piece is permanently maintained.

A thrust piece that can be used for clamping can also already be connected to the moulded part, for example via a hinge or joint.

The hinge or joint allows the thrust piece to be pivoted relative to the moulded part in order to insert it into a recess in the moulded part.

The thrust piece must then be secured in position to apply the required clamping force.

The position can be secured by means of a force-fitting and/or form-fitting connection of the thrust piece to the moulded part.

If several thrust pieces are provided that are not already connected to the moulded part, they can be connected to one another.

For example, by means of a type of bracket which can also be used as a handle element and facilitates insertion of the thrust pieces into the recesses.

According to the invention, the moulded part is connected in a force-fitting and/or form-fitting manner to a carrier element made of plastic, which is equipped with a measuring resistor, preferably in the form of an SMD component.

The function of the moulded part is to hold the measuring resistor or the SMD component in position.

The moulded part thus serves as a component holder.

The proposed electrical sensor, in particular temperature sensor, has preferably been produced according to the method according to the invention described above.

Production by the method according to the invention and/or the use of a moulded part according to the invention in production enable a high degree of automation, so that production costs can be reduced.

According to the invention, a connecting wire (or a stranded wire) is inserted in the at least one guide channel of the moulded part and is electrically connected, preferably soldered and/or clamped, to an electrical connecting surface of the measuring resistor in the area of the recess.

In this embodiment of an electrical sensor, several functions of the moulded part come into play at once during the production of the sensor.

In particular, the moulded part can be used as a guide element, positioning aid and/or soldering jig.

Furthermore, the moulded part can be used as an insulating component for electrically insulating the connecting wire (or stranded wire) from at least one further connecting wire (or stranded wire) if the latter is inserted into a further guide channel,

12 17179042.1 which is preferably arranged at a distance from and/or running parallel to the first guide channel. Ideally, therefore, the carrier element and/or the moulded part is/are made of an electrically insulating and thermally conductive plastic. To protect the electrical sensor according to the invention from external influences, it is proposed that the carrier element, the measuring resistor and/or the moulded part are at least in areas encapsulated with a plastic and/or surrounded by a housing. The measures — individually or in combination — help to ensure that the measuring resistor is optimally protected against external influences; in particular, sealing can be achieved. Accordingly, the robustness of the electrical sensor increases, making it versatile. If the electrical sensor is a temperature sensor, the carrier element, the measuring resistor and/or the moulded part are preferably overmoulded at least in areas with a thermally conductive plastic. The thermally conductive plastic contributes to the sensor's fast response and a high degree of measurement accuracy. The invention is explained in more detail below with reference to the accompanying drawings. The drawings show:

Fig.1 a top view of an electrical sensor according to a preferred embodiment of the invention before overmoulding with plastic,

Fig. 2 a perspective view of the electrical sensor of Fig. 1,

Fig.3 a cross-section through the electrical sensor of Fig. 1,

Fig. 4 a side view of the electrical sensor of Fig. 1 after overmoulding with plastic,

Fig. 5 a top view of the moulded part of the electrical sensor of Fig. 1,

Fig. 6 a side view of the moulded part of the electrical sensor of Fig. 1,

Fig. 7 a side view of the moulded part of the electrical sensor of Fig. 1 rotated by 907,

Fig. 8 a perspective view of a modified moulded part according to the invention with thrust piece for clamping a connecting wire, and

Fig. 9 a perspective view of the thrust piece of Fig. 8. Detailed description of the drawings The electrical sensor 1 shown in Fig. 1 comprises an elongated, semi-circular cross- section carrier element 2, which is equipped with a measuring resistor 3. The measuring

13 17179042.1 resistor 3 is an SMD component which has no connecting wires but electrical connecting surfaces 5, 6. The SMD component is inserted flush into a recess 9 of the carrier element 2 (see Fig. 3). To further fix the position of the SMD component, a moulded part 4 with recesses 10, 11 is plugged onto the carrier element 2 so that the recesses 10, 11 come to lie in the area of the electrical connection surfaces 5, 6 of the measuring resistor 3. The window- like recesses 10, 11 serve to expose the electrical connection surfaces 5, 6 so that they can be electrically connected to connecting wires 7, 8, which are accommodated in guide channels 13, 14 of the moulded part 4. The electrical connection can be made by soldering, for example. The plug-in connection of the moulded part 4 with the carrier element 2 is made via pin-shaped connecting means 15, which are formed on a support surface 16 of the moulded part 4 facing the carrier element 2 and engage in corresponding recesses 17 of the carrier element 2. The guide channels 13, 14 extend in the longitudinal direction of the moulded part 4 and are guided parallel to one another at a distance. The guide channel 13 accommodating the connecting wire 7 is longer than the guide channel 14 accommodating the connecting wire 8, since the measuring resistor 3 is oriented in such a way that the electrical connection surfaces 5, 6 come to lie one behind the other in the longitudinal direction of the moulded part 4. This causes a spatial ordering of the electrical connection points so that the risk of a short circuit is eliminated. Accordingly, the two window-like recesses 10, 11 of the moulded part 4 are also arranged at a distance from one another. In addition, the recesses 10, 11 are offset from one another in the transverse direction of the moulded part 4, which takes into account the fact that the guide channels 13, 14 run parallel to one another at a distance for the electrical insulation of the connecting wires 7, 8 accommodated therein. As shown in particular in Fig. 3, the connecting wires 7, 8 accommodated in the guide channels 13, 14 come to lie over the electrical connection surfaces 5, 6 of the measuring resistor 3. This means that a certain gap remains for making the electrical connection by means of soldering. After soldering, the gap is filled by the solder (not shown).

Fig. 2 shows that the carrier element 2 can be significantly longer than the moulded part. In the area of the extension, the carrier element 2 has guide webs 18 between which the connecting wires 7, 8 are inserted.

14 17179042.1

In this way, additional guidance of the connecting wires 7, 8 over the carrier element 2 is achieved.

The guidance of the connecting wires 7, 8 proves to be an advantage, especially during the production of the sensor 1. This is because, due to the guide, the connecting wires 7, 8 can be shot in, so that production of the sensor 1 can be automated, at least to a large extent.

Preferably, during the production of the sensor 1, the measuring resistor 3 is first inserted into the recess 9 of the carrier element 2, and then the moulded part 4 is plugged onto the carrier element 2. The connecting wires 7, 8 are then shot in, wherein the moulded part 4 serving as a guide element and positioning aid.

This is because the respective position, in particular end position, of the connecting wires 7, 8 is precisely specified via the guide channels 13, 14 and the window-like recesses 10, 11. The ends of the connecting wires 7, 8 come to lie exactly over the electrical connection surfaces 5, 6 of the measuring resistor 3, so that the electrical connection can be made by soldering via the window-like recesses 10, 11. The moulded part 4 serves as a soldering jig.

The production of the sensor can thus be fully automated.

Finally, the sensor 1 can be overmoulded or partially overmoulded with plastic 12, which is preferably an electrically insulating and thermally conductive plastic 12. The sensor 1 of Fig. 1 with a corresponding partial overmoulding of plastic 12 is shown by way of example in Fig. 4. The plastic 12 is moulded onto the carrier element 2 in such a way that the moulded part 4 is completely surrounded by plastic 12. In this way, an optimum seal is achieved.

Due to the partial overmoulding of plastic 12, the sensor 1 has a circular cross-section.

This facilitates insertion of the sensor 1 into a housing 31, if desired.

A housing 31 is optional and may be provided as an alternative or in addition to overmoulding with plastic 12.

Figures 5 to 7 show a top view and various views of the moulded part 4 of the sensor 1 shown in Figures 1 to 4.

The top view of Fig. 5 in conjunction with the side view of Fig. 6 and/or of Fig. 7 shows that the moulded part 4 has essentially the shape of a flat elongated cuboid.

On the upper side, i.e. on the side facing away from the supporting surface 16, the corners are rounded.

The upper side also has a web 21 arranged approximately in the centre and running in the transverse direction, which serves as a handle element.

At the web 21, the moulded part 4 can be gripped and displaced, to connect it to a carrier element 2, for

15 17179042.1 example. On the underside, i.e. on the support surface 16, the moulded part 4 has two pin-shaped connecting means 15 for form-fitting connection to the carrier element 2. As shown in particular in Fig. 5, the moulded part 4 further has two window-like recesses 10, 11, which are arranged at a distance from one another in the longitudinal direction of the moulded part 4. In the transverse direction of the moulded part 4, the two recesses 10, 11 are offset from one another. The offset in the transverse direction ensures that each guide channel 13, 14 for receiving a connecting wire 7, 8 ends in a recess 10, 11. This is because the offset of the recesses 10, 11 in the transverse direction essentially corresponds to the distance between the two parallel guide channels 13, 14 (see also Fig. 7). The guide channel 13 ends in the recess 10 and the guide channel 14 in the recess

11. Since the moulded part 4 is made of an electrically non-conductive plastic, electrical insulation of the connecting wires 7, 8 inserted therein can be achieved at the same time via the spacing of the guide channels 13, 14 formed in the moulded part 4, providing the moulded part 4 is made of an electrically insulating material, in particular plastic. The recesses 10, 11 provided in the moulded part 4 enable the moulded part 4 to be used as a soldering jig when an electrical connection of a connecting wire 7, 8 inserted in a guide channel 13, 14 is to be made by soldering to an electrical connection surface 5, 6 of a measuring resistor 3. As shown in Figures 5 to 7, the recesses 10, 11 may each have at least one limiting flank 26, 27 that is oblique with respect to the support surface 16. As a result, the recesses 10, 11 form a kind of funnel that simplifies the method of making the soldered joint between a connecting wire 7, 8 and an electrical connection surface 5,

6. Figures 8 and 9 show another preferred embodiment of a moulded part 4 according to the invention for producing an electrical sensor 1. The moulded part 4 is characterized by connecting means 20, each arranged on two opposite sides of a recess 10, 11, for form- fitting connection of a thrust piece 19 received in the recess 10, 11 to the moulded part

4. In turn, the thrust piece 19 is used to establish the electrical connection of a connecting wire 7, 8 with an electrical connecting surface 5, 6 of the measuring resistor 3 by clamping. For the sake of simplicity, Fig. 8 shows only one thrust piece 19, which is inserted into the recess 10. In the same way, another thrust piece 19 is preferably inserted into recess 11 (not shown).

16 17179042.1 Furthermore, in the area of the recess 10, only one connecting means 20 for form- fitting connection of the thrust piece 19 to the moulded part 4 is shown in order to keep the drawing clear. Preferably, another connecting means 20 is provided in a mirrored arrangement on the opposite side of the recess 10, so that snap-in lugs 28 arranged at the ends of each connecting means 20 engage behind the thrust piece 19 and hold it down. In this way, the clamping force required to clamp the connecting wires 7, 8 can be applied. In Fig. 8, a bracket 22 is also indicated, via which the thrust piece 19 is connected or can be connected to a further thrust piece 19 (not shown). The bracket 22 facilitates the insertion of the thrust pieces 19 into the recesses 10, 11, since both thrust pieces 19 can be mounted simultaneously. In this case, the bracket 22 can serve as a handle element for lifting and displacing the thrust pieces 19. In addition to the recesses 10, 11, the moulded part 4 of Fig. 8 has several inflow holes 23 which also penetrate the moulded part 4. In the process of overmoulding with plastic, the plastic melt can thus penetrate between the moulded part 4 and the carrier element 2. If this is not desired, the inflow holes 23 can also be omitted.

Fig. 9 shows the thrust piece 19 of Fig. 8 individually. In the present case, the thrust piece 19 is essentially L-shaped, so that a leg 29 is formed with a support surface 25 on the end face, via which the thrust piece 19 can be supported on the carrier element 2. This is because the thrust piece 19 is preferably not inserted into the recess 10 until after the moulded part 4 has been connected to the carrier element 2. The other leg 30 of the thrust piece 19 has a guide 24 on its side facing the carrier element 2, in which the connecting wire 7 comes to lie when the thrust piece 19 is inserted into the recess 10 and connected to the moulded part 4 via the connecting means 20. In this way it is ensured that the connecting wire 7 comes into contact and therefore into electrically conductive contact with the electrical connection surface 5 of the measuring resistor 3. The invention is not limited to the preferred embodiments shown in Figures 1 to 9, but also includes variations within the scope of the claims. These may relate in particular to the specific design of the moulded part 4 with respect to its connecting means 15 and/or the position, shape and/or size of the recesses 10, 11. Furthermore, the carrier element 2 of a sensor 1 according to the invention can be designed in deviation from the illustrations of Fig. 1 to 4. List of reference numerals

17 17179042.1 1 Sensor 2 Carrier element 3 Measuring resistor 4 Moulded part

5 Connection surface 6 Connection surface 7 Connecting wire 8 Connecting wire

9 Recess 10 Recess 11 Recess 12 — Plastic, plastic overmoulding 13 Guide channel

14 — Guide channel 15 Connecting means 16 Support surface 17 Recess 18 Guide web

19 — Thrust piece 20 Connecting means 21 Web, handle element 22 Bracket, handle element 23 — Inflow hole

24 — Guide 25 — Support surface 26 — Flank 27 — Flank 28 — Snap-in |ug

29 Leg 30 Leg 31 Housing